Bhandari, a three-term former chief minister, is survived by his wife Dil Kumari Bhandari, a former MP, two daughters and a son.
Prime Minister Narendra Modi condoled his demise, saying his contribution towards Sikkim's progress will always be remembered.
"Saddened by demise of Shri Nar Bahadur Bhandari. His contribution towards Sikkim's progress will always be remembered. My condolences," said Prime Minister Modi.
Current Sikkim Chief Minister Pawan Chamling?, Union Home Minister Rajnath Singh, Minister of State for Home Affairs Kiren Rjiju, Railway Minister Suresh Prabhu also took to Twitter to express their grief.
"Saddened by the sudden demise of Shri NB Bhandari former CM Sikkim. May he RIP.
My condolences to the bereaved family ," tweeted Chamling.
"Former CM of Sikkim, Shri Nar Bahadur Bhandari was a people's man and a pragmatic leader. Anguished by the news of his sudden demise. I offer my heartfelt condolences to the bereaved family of Shri Nar Bahadur Bhandari. May God give them strength to bear this tragic loss," said Rajnath.
"I extend my deep condolences to the bereaved family of Shri Nar Bahadur Bhandari ex-CM of Sikkim who passed away today," tweeted Rijiju.
"Pained and saddened by the passing away of Shri Nar Bahadur Bhandari,former CM of Sikkim. My heartfelt condolences. RIP," said Prabhu.
Born in 1940 at Malbasey in West Sikkim, Bhandari completed his BA degree from Darjeeling Government College and worked as a school teacher for some years before joining politics.
In 1984, he also served briefly as Member of Parliament from Sikkim constituency in the eighth Lok Sabha as an independent candidate.
He became the chief minister of Sikkim for the first time in 1979 and then again in 1984 and 1989.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)